The support for Unix-sockets in interactions between searchd and search.cgi has been added in the latest snapshot of DataparkSearch Engine.
To configure a Unix-socket to answer on by searchd you need to specify the following command in searchd.conf file:
Socket dpsearchd.sock
You can use any name instead of dpsearchd.sock. By default, unix-socket is created relative to the directory specified by VarDir command, although the full path to a socket can be specified as well (please take in account the limit in 128 character to full pathname for a unix-socket).
To specify Unix-socket connection in search template search.htm use socket parameter for DBAddr command:
DBAddr searchd://localhost/?socket=/usr/local/dpsearch/var/dpsearchd.sock